Facebook's IPO is coming in the spring of 2012.

Despite a report to the contrary, our sources tell us Facebook is still planning a spring IPO in 2012.

Our analysis: Even though revenue numbers leaked earlier this year were lower than expected, Facebook is still growing very rapidly. An anonymous source told Reuters that Facebook earned $500 million on $1.6 billion in revenue during the first half of 2011. That's about twice as much as it earned and booked during the first half of 2010.

Shares are trading as high as $80 billion on Sharespost, at approximately the same level where they've been trading for the past 6 months. This is about ~60X this year's projected earnings and 20X revenue. These are high multiples, and for this valuation to be sustained, the company will have to continue to grow extremely rapidly.

The company is on track to generate about $1.5 billion of revenue this year (extrapolating from its S-1 filing), from a combination of ads and virtual goods. This is up from $597 million last year. The company's operating profit on this revenue is still low--about 10% of revenue--but this margin will presumably expand as the company gains scale. We use a multiple of 7X revenue and arrive at a valuation of about $11 billion.

Groupon is weeks away from its roadshow.

Groupon has seen its fair share of controversy since filing its S1 to go public. Its losses are shocking, and if it doesn't raise money through the public markets, it will be in serious trouble. But, the company is on pace to do just that in the next few weeks.

Our analysis: Groupon began the year strong when it turned down a $6 billion buyout offer from Google in December. Since then its road to an IPO has been bumpy. The SEC was investigating the company after a detailed memo about its business was leaked to the press during the "quiet period," but now the IPO roadshow is said to be back on.

Groupon has invented a new form of marketing that has become as much a part of everyday advertising and commerce as classified ads used to be. Groupon has been so wildly successful that, in the space of a year, more than 100 Groupon clones have sprung up to capitalize on the "daily deal" concept. In recent months, however, many concerns about the Daily Deal model have arisen, and some are speculating that Groupon's years of rocketship growth will soon be behind it.

Given the company’s market lead and continued user growth, we give Groupon a 3-4X multiple on revenue for a valuation of $10 billion. Shares have sold at a valuation as high as $14.9 billion on Sharespost.

Twitter already has Morgan Stanley as an investor.

Twitter just raised $800 million, but the company is growing so fast it should be ready to IPO soon enough, especially if market conditions improve.

Our analysis: Back in 2009, Morgan Stanley contributed $10 million to a $100 million round, giving the investment bank an in when Twitter decided to go public (and Twitter's executives a way to land free advice). The company boasts an $8 billion valuation and is reportedly generating $150 million in revenue this year.

They raised two massive rounds this summer, but a lot of that cash went toward paying employees. There is still plenty in the bank but an IPO can't be that far off.

Dropbox settled for a low valuation, but it is still worth $4 billion.

The free Internet sharing service exploded over the past 12 months and saw its valuation skyrocket.

Our analysis: Before Dropbox raised a round this summer, rumors pegged the value at $8 billion. The company closed the Index Ventures-led round at a $4 billion valuation. Tough market conditions lowered the figure (although there are rumors Dropbox wanted to pick and choose its investors and settled to do so).

The world is only going to need more storage as online video grows. Dropbox's costs are always going to go down, because cloud computing costs are always getting cheaper. On the revenue side, Dropbox's revenues are always going to go up. It's a freemium business model, and freemiums works best when the value of the services go up over time. Most people won't pay to back up a few files on Dropbox. They'll pay to store them all.

Living Social will learn from Groupon

Living Social is the second-biggest player in the daily deals market.

Our analysis:LivingSocial is a group buying platform that invites users to local attractions in major cities at deeply discounted rates (usually between 50-80% off). LivingSocial is on track to generate revenue of $1 billion in 2011, which is still significantly less than market-leader Groupon. Using the same 3X revenue multiple we gave Groupon, we give LivingSocial a $3 billion valuation.

Roughly $200 million of the $400 million the company raised in April 2011 went into the company's coffers. They will learn a lot about the market conditions from Groupon's IPO experience.

Tumblr just raised $85 million.

David Karp's vision became a massive cultural phenomenon in 2010 with over 13 billion pageviews per month.

Our analysis: Tumblr raised $85 million at an $800 million valuation. They won't need cash for a a while - and aren't likely to file an S-1 soon, especially if they don't figure out how to increase revenue - but the surging growth makes them a business to watch.

Square has a way to go, but it could be huge.

Jack Dorsey's newest company made a huge valuation leap in 2010 and is now worth around $1.6 billion.

Airbnb is another company that came from out of nowhere.

This time last year, almost no one had heard of the short-term apartment rental service. Today, it's worth more than $1 billion.

Our analysis: Airbnb is a short-term apartment rental service. The company raised $112 million in July, but Airbnb is not without its issues. Users have publicly complained about their apartments being destroyed by other Airbnb users. Reports suggest that Airbnb will do north of $500 million of gross merchandise sales in 2011, and book net revenue of about 5% of that.

Airbnb has plenty of work to do before (if) it goes public, but the structure is there. They have a real business model and a huge leg up on any competition.